<!DOCTYPE html>
<div id="container">
  x
  <span style="-webkit-mask:url(#boink);">y</span>
</div>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script>
requestAnimationFrame(()=> {
    requestAnimationFrame(()=> {
        container.style.width = "0";
    });
});
test(()=> { }, "no crash");
</script>
